Tight Bounds of Differentially and Linearly Active S-Boxes and Division Property of Lilliput.

This paper provides security analysis of a lightweight block cipher called LILLIPUT, which was proposed in IEEE Transactions on Computers in 2015. LILLIPUT adopts an extended generalized Feistel network (EGFN). EGFN consists of non-linear, linear, and permutation layers, and the linear layer updates a part of the state only linearly, which causes several security concerns. Our first discovery is t...